The present invention relates to an absorbent article, such as a sanitary towel, an incontinence protector, a diaper, a seat protector or a bed protector, comprising an absorption body enclosed between a liquid-permeable cover layer and a liquid-tight cover layer, which liquid-tight cover layer comprises a carrier layer having a first surface and a second surface, the first surface being intended to function as a securing arrangement for securing on a textile surface or textile-like surface. The invention also includes a diaper with a securing arrangement according to the invention, for fastening the article in a shape similar to pants.
The most common way of securing a sanitary towel inside a pair of pants during use is to arrange a securing surface, in the form of a self-adhesive, on that side of the sanitary towel which, during use, is intended to be in contact with the user""s pants. In order to avoid problems associated with the stickiness of the adhesive surface during storage and transport of the sanitary towels, the securing adhesive is usually protected by a separate detachable strip of paper or the like which has been treated with a release agent. When the sanitary towel is to be used, the protective strip is removed so that the adhesive is exposed and can be used for securing the sanitary towel in the user""s pants. The protective strip fulfils no other function and is thrown away once it has been detached from the securing adhesive. The use of such protective strips involves a number of disadvantages. For example, it is awkward to handle the protective strips when the sanitary towel is to be used, especially if the sanitary towel is provided with several different protective strips which need to be removed. In addition, the use of protective strips means that a lot of material is unnecessarily used up, which is a disadvantage from the environmental and energy points of view and also from the point of view of cost.
A further inconvenience with a self-adhesive placed on the liquid-tight cover layer for securing the article to the pants is that it is difficult to place the article inside a pair of pants without the article folding or deforming during positioning. The folding or deformation can lead to adhesive coming into contact with adhesive. These articles are then very often unusable, since it is difficult to free the stuck contact areas from each other without destroying the article. If an article in this condition is still used, there is a high risk of liquid leaking out. The problem is associated principally with incontinence protectors and other articles used by the elderly or handicapped persons with reduced mobility of the hands, but the problem also arises when using sanitary towels.
In order to eliminate the separate protective strips, it is already known to provide a sanitary towel both with adhesive areas and with areas which have been treated with release agent, these being arranged in such a way that the sanitary towel can be folded up with the adhesive areas bearing against, and protected by, the areas which have been treated with release agent. Sanitary towels of this kind are described in U.S. Pat. No. 4,376,440, EP 471,385, EP 471,386 and EP 471,387. Such an arrangement reduces the amount of material used up, and to some extent simplifies the handling of the sanitary towel. An important problem, however, is that the possibility of arranging the securing adhesive in the manner which affords the best attachment of the sanitary towel inside the user""s pants is greatly restricted since the positioning of the adhesive surfaces must in the first instance be chosen in such a way that, after the sanitary towel has been folded up, the adhesive surfaces bear against the corresponding areas that have been treated with release agent. In addition, there is still the problem of the article folding as it is being placed in the pants, resulting in undesired sticking together of the adhesive surfaces.
EP 393,953 has already disclosed a pressure-sensitive securing arrangement which comprises a support whose one side is provided with a pressure-sensitive adhesive, arranged in the spaces between a number of barbs or projections protruding from the support, the barbs or projections extending beyond the adhesive. The securing arrangement is particularly suitable for use on fabrics, the barbs or projections being able to penetrate down through the surface of the fabric so that the adhesive is brought into contact with and sticks to the fabric. The disadvantages of this known type of securing arrangement are mainly that it is stiff and hard and thus can easily cause chafing and other discomfort for the user. In addition, the protruding barbs pose a certain risk of damage to the surface on which the arrangement is secured. Moreover, the securing arrangement is relatively expensive and complicated to produce. A similar adhesive securing arrangement is described in U.S. Pat. No. 4,376,440.
Another sanitary towel having an adhesive securing arrangement is described in EP 234,194 and in EP 229,639. The known sanitary towel comprises a pressure-sensitive adhesive securing layer, and an elastic foam material layer arranged outside the adhesive layer and provided with openings through which the adhesive is exposed for securing purposes. Such a securing arrangement, however, does not have a sufficiently large available securing surface area to permit satisfactory securing. Moreover, there are difficulties involved in producing the known sanitary towel, since a web of foam material is relatively fragile and easily breaks when subjected to the tensile stresses that arise at high production speeds. In addition, at high production speeds, it is difficult to monitor and control the stretching which occurs in the elastic foam material. Moreover, the foam material is expensive and difficult to produce in the form of layers that are sufficiently thin to allow the adhesive to act through the foam material. A thick, bulky material is also difficult to handle in a continuous process since it requires frequent roller changes, which of course has a negative impact on efficiency and cost.
An adhesive securing arrangement for securing a sanitary towel inside a pair of pants is also described in U.S. Pat. No. 3,888,255. The securing arrangement comprises an elastic foam material layer having a coefficient of friction greater than 2. A pressure-sensitive adhesive layer is arranged on the elastic foam material layer. Such a securing arrangement, however, requires a separate detachable protective strip of paper or the like that has been treated with release agent. Also, it is difficult to free adhering contact areas from each other if the article becomes folded during actual securing in the pants.
Another problem with the previously known sanitary towels having a securing arrangement in the form of a self-adhesive coating is that it is difficult to regulate the degree of stickiness so that the latter is sufficient regardless of what material the user""s pants are made of. The stickiness will be different for different textile materials, and one and the same adhesive coating will, for example, secure several times better against a surface made of nylon, or nylon-like material, than against cotton material. In the case of an adhesive coating which provides sufficiently good securing in pants made of cotton, there is a risk that a pair of pants made of nylon or the like will be damaged when the sanitary towel is removed, or that residues of adhesive will remain on the pants.
Diapers of the type mentioned at the outset are usually secured with tape flaps which are secured against a reinforced plastic surface on the front portion of the diaper. Although such a securing arrangement provides satisfactory securing of the diapers, it also has some disadvantages. For example, it is difficult to protect the tape flaps before use. In the known diapers, this problem is solved by the fact that the flaps are folded in over surfaces that have been treated with release agent, either on the tapes themselves or on the diaper. Folded tapes are expensive and difficult to produce and arrange on the diapers and are the cause of a relatively large proportion of the waste which arises in the manufacture of the diapers. In addition, it can be difficult to release the tape from the surface treated with release agent when the diaper is to be used. Particularly in cases where the diaper is to be placed on an extremely lively child, flaps that are difficult to open can be a nuisance. To increase the ease of handling of the tape flaps, these are made of fairly stiff material, which easily gives rise to sharp corners and edges that can cause chafing and irritation to the user""s skin. Another arrangement for securing a diaper round the user""s waist is to use mechanical securing members such as, for example, velcro-type seals. The disadvantage of such securing members is, however, that they are expensive to produce. Moreover, they have a relatively high rigidity, which can cause chafing and irritation to the user""s skin.
The present invention provides an absorbent article, such as a sanitary towel, an incontinence protector, a diaper, a seat protector or a bed protector, which, during use, is very soft and pliable and does not cause chafing. The absorbent article also provides good securing against textile surfaces or textile-like surfaces.
The absorbent article comprises an absorption body enclosed between a liquid-permeable cover layer and a liquid-tight cover layer, which liquid-tight cover layer comprises a carrier layer having a first surface and a second surface, of which the first surface functions as a securing arrangement for securing on a textile surface or textile-like surface, and is distinguished primarily by the fact that a multiplicity of individual fibres, which are free from one another and each have two fibre ends, are secured via one fibre end to the first surface of the carrier layer, and moreover by the fact that the first surface, in order to serve as a securing surface against a textile material surface or textile-like material surface, is at least partially coated with an adhesive.
With a securing arrangement, for an absorbent article, comprising a multiplicity of fibres, a soft securing arrangement is obtained which is discreet and easy to wear and which does not cause chafing against the user.
The degree of sticking to a textile surface or textile-like surface can be varied, not only through the amount and choice of adhesive, but also through the choice of fibres, fibre density, and length of the fibres. This makes it possible to obtain an adhesion which is suitable for different types of textile surfaces or textile-like surfaces. In addition, it is possible to have a very thin adhesive layer, or a not completely covering adhesive layer, since the individual fibres themselves give the surface of the securing arrangement greater friction than does an essentially smooth surface without fibres. It is therefore not necessary for all the fibres on the fibre surface to have an adhesive coating.
A discontinuous, not completely covering adhesive layer can be obtained, for example, by spraying the adhesive onto the support in the form of small drops or fibres. In addition, the desired adhesion can be obtained by means of only certain areas or zones of the total surface being coated with adhesive. A not completely covering adhesive layer eliminates the need for a separate detachable strip of material for protecting a securing adhesive surface during storage and transport.
Another advantage of the securing arrangement is that the risk of the pants being damaged when the article is being removed, or of residues of adhesive being left behind, is almost completely eliminated. In addition, with such a securing arrangement, it is easy to adjust the position of the article if the article ends up in the wrong position at the time of securing or becomes folded or displaced during use.
A further advantage of the present securing arrangement is that it is relatively simple to produce. The fibres are preferably oriented against a carrier layer by a flocking technique. The fibres are secured to the carrier layer by gluing, or by means of at least one component in the carrier material or in the fibres being heated during the flocking procedure to a temperature in excess of the melt temperature of the component.
According to one embodiment, the adhesive is a self-adhesive. The securing on the textile surface or textile-like surface is thus obtained both mechanically, by means of the fibre surface having a high degree of friction on the textile surface, and also adhesively, by means of the securing surface being completely or partially coated with the self-adhesive. Thus, with such a securing arrangement, it is possible to obtain a softer and more pliable securing arrangement compared to exclusively mechanical securing arrangements, such as various types of velcro closures. In addition, there is no need, as there is in the case of purely adhesive securing arrangements, to provide a separate detachable strip of material for protecting the securing adhesive surface prior to use.
One embodiment is characterized in that the carrier layer is coated with a self-adhesive, after which the multiplicity of individual fibres are applied and secured on the adhesive-coated surface of the carrier layer. According to this embodiment, therefore, the applied fibres do not have any adhesive coating. The advantage of such an embodiment is that the self-adhesive is protected from undesired contact with other material by means of the applied fibre layer which creates a distance between the adhesive layer and other contact surfaces. On sticking to a textile-like material, however, the self-adhesive layer arranged under the fibres functions to increase the stickiness by means of contact being obtained between the receiving material and the self-adhesive layer when an external pressure is applied. A further advantage of such an embodiment is that the adhesive, apart from strengthening the securing of the article during use, also secures the fibres to the carrier layer surface during the actual application of the fibres. In this way, a further adhesive for securing the fibres is eliminated.
According to another embodiment, the adhesive is applied after the fibres have been arranged on the carrier layer, for example by spraying the adhesive onto the fibre-coated surface. This creates a non-covering adhesive layer on the fibre surface. An advantage of such an embodiment is that no great pressure needs to be applied to secure a receiving material to such a securing arrangement. In addition, there is very little risk of the pants being damaged when the article is being removed or of residues of adhesive being left behind.
It is advantageous if the adhesive secures at least to the free, outer end of the fibres. In such an embodiment, it is also possible for the adhesive to be one which solidifies after application. The idea of this embodiment is that the adhesive is applied so that it binds on the fibre surface and creates an uneven surface structure presenting small projections of applied adhesive along the fibre surface on the outer, free fibre end, or, alternatively, along the entire fibre surface. These projections provide increased mechanical securing against a textile-like surface.
In order to increase the mechanical securing capacity, it is also possible to use fibres having a curved fibre end. These curved fibre ends are obtained, for example, by the free fibre end of the fibres being heated to the softening point of the fibres, or to the melt temperature of the fibres. This creates curved fibre ends or, alternatively, a melted fibre edge which has a deformed, hook-like end portion. A curved fibre end or melted edge increases the possibility of the securing arrangement hooking securely in a textile-like material.
According to another embodiment, the first surface of the carrier layer has certain areas which are free from fibres. Such an embodiment is advantageous for increasing the adhesive securing capacity for a securing arrangement having an adhesive-coated carrier layer, and fibres which are not adhesive-coated. If the first surface of the carrier layer also has small surfaces which are free from secured fibres, the free adhesive-coated surface is protected by the fibres which are secured around the free fibre surface. This means that no separate detachable strip of material is needed for protecting the adhesive securing surface prior to use. Another advantage of such an embodiment is that the consumption of fibres is reduced. A further advantage of such an embodiment is that it is possible to create a specific, desired pattern and thereby achieve an aesthetically pleasing appearance of the surface of the securing arrangement.
According to one advantageous embodiment, the carrier layer also constitutes the liquid-tight cover layer of the article. The carrier layer thus consists of a liquid-tight material layer, such as, for example, a plastic film. The advantage of such an embodiment is that a joining bridge between the liquid-tight cover layer and the carrier layer is eliminated. The material consumption is also reduced, which is of importance from the point of view of cost as well as from the environmental aspect. It is also possible to produce an article which is softer and more pliable than when separate material layers are used as a liquid-tight cover layer and a carrier layer.
The invention also includes a diaper comprising a first, liquid-permeable cover layer, and a second, liquid-tight cover layer, which two cover layers are connected to each other around an absorption body enclosed between the cover layers. The diaper has a front portion, a rear portion, and a crotch portion situated between these two portions, and moreover two longitudinal side edges and a front waist margin and a rear waist margin, which two waist margins are designed to surround a user""s waist and thus form the waist opening of the diaper. The diaper moreover comprises at least one fastening arrangement for fastening the article in a shape similar to pants, the fastening arrangement comprising a first component member and a second component member arranged at each side edge, the component members being designed to cooperate with each other for fastening the article. The securing arrangement is distinguished primarily by the fact that at least the first component member comprises a carrier layer having a first surface and a second surface, the first surface being intended to cooperate with the second component member for fastening the article, and against which surface a multiplicity of individual fibres, which are free from one another and each have two fibre ends, are secured via one fibre end, and by the fact that the first surface, in order to serve as a securing surface against a textile material surface or textile-like material surface, is coated with an adhesive. The design of the first component member for securing the diaper in a shape like pants by means of a securing arrangement according to the invention also covers all embodiments in the descrtiption and claims.
According to one embodiment, the second component member also consists of a carrier layer against which a multiplicity of individual fibres are secured via one fibre end. The second component member is either adhesive-coated or free from such adhesive coating. An advantage of adhesive-coated second component members is that an increased adhesive securing capacity is achieved. In addition, such a diaper is easier to produce, since only one securing material is used. Nevertheless, from environmental considerations, it may be more advantageous to have second component members which are free from adhesive.